3D Printer Guns on the Agenda

[Ben]

Looks like the grabbers have discovered 3D printer tech. Interesting how when the Democratic rep refers to the builders he cites them as "kids", but in many other circumstances would refer to them as adults.

http://www.foxnews.com/us/2012/12/21/development-future-downloadable-guns-worries-activists/?test=latestnews

[AJ Dual]

I'm fine with this.

Giving the anti's more and more to worry about will eventually cause "issue overload" and cause them to dilute their message.

[kgbsquirrel]

Well. At least the stupid is predictable.

[HankB]

Once the technology is commonplace and CHEAP, just imagine the potential when the grabbers sponsor "no questions asked" gun buybacks in places like NYC, Chicago, LA, etc. 

[kgbsquirrel]

Once the technology is commonplace and CHEAP, just imagine the potential when the grabbers sponsor "no questions asked" gun buybacks in places like NYC, Chicago, LA, etc. 

.......

Hank, I think you just figured out how to fund my early retirement.

[AmbulanceDriver]

Oh....   that's just awesome

Once the technology is commonplace and CHEAP, just imagine the potential when the grabbers sponsor "no questions asked" gun buybacks in places like NYC, Chicago, LA, etc. 

[longeyes]

Like all good things it will go "underground."

"Silence, exile, cunning."

[Jamisjockey]

Once the technology is commonplace and CHEAP, just imagine the potential when the grabbers sponsor "no questions asked" gun buybacks in places like NYC, Chicago, LA, etc. 

Considering the utter stupidity at these buy backs, I'd imagine that the guns could be horribly made and non functioning, too.

[freakazoid]

Considering the utter stupidity at these buy backs, I'd imagine that the guns could be horribly made and non functioning, too.

I remember reading stories of people doing that with old no longer functioning guns a while back.

[RevDisk]

No way you could build an upper with it. Stock, handgrip, sure. Barrel?  Only an anti-2A would be dumb enough to believe that.

Now, when you can laser sinister a barrel, gimme a call.

[just Warren]

Sinister?

[Cliffh]

But would one be able to "build" a barrel that looks good enough to pass the "inspection" at a buy-back?

[Doggy Daddy]

Sinister?

Latin for "left".

[AJ Dual]

Latin for "left".

He meant sintered. Powdered metal fused by lasers. Just in case someone didn't understand the word switch Rev's phone pulled on him there and people aren't being obtuse for laughs. 

I think if someone really wanted to, they probably could produce a single use "Liberator" type that would at least be as lethal as a cap n ball Derringer from the 1860-70's out of ABS, or whichever printable resin has the best characteristics for it. Maybe even a multi-shot pepperbox type. High caliber, low pressure and velocity. Just toss it when it's empty.

It probably actually would be a muzzleloader technically, not even containing cartridges, just a primer/cap, powder, and a bullet or ball, unless perhaps they decided that actual cartridges worked better after some experimentation. Perhaps you could even do electrical ignition, kind of like the "Metalstorm" concept firearms. A Roman Candle tube of bullet/powder/bullet/powder/bullet/powder, a switch for the trigger, a battery, and a simple IC that lit ignition wires in the right sequence.

The guys who pulled HaveBlue's lease on their printers have some ideas. http://www.stratasys.com/Resources/White-Papers/Thermoplastics-the-Best-Choice-for-3D-Printing.aspx 

Maybe polycarbonate bores/chambers, covered in ABS for resilience?

[Doggy Daddy]

He meant sintered. Powdered metal fused by lasers. Just in case someone didn't understand the word switch Rev's phone pulled on him there and people aren't being obtuse for laughs. 

Now, that's probably right! 

[Fly320s]

Sinister?

Guns are evil, dontcha know?

Latin for "left".

Especially left-handed guns.

[kgbsquirrel]

For the record, I think you could make an upper if you reinforced/thickened it sufficiently. In the AR design the aluminum upper and lower halves actually play no part in containing the cartridge during firing. The locking lugs are part of the barrel extension which is more or less permanently screwed onto the barrel. The bolt itself locks into this barrel extension. The only stresses the upper and lower halves deal with are transferring recoil energy, and keeping all the mechanical parts in their correct places during cycling.

Still, and while this isn't a true total plastic design, I think taking bits of small diameter steel rod that you can get at the hardware store, and carefully integrating them into the plastic part as it's being built up by the printer might be a good stop-gap until we get good plastics that can handle the job on their own. Heck, most of the "polymer" parts you have in the gunsmithing industry currently are fiberglass reinforced.


As for making a Liberator Mk-II, a ball and cap pepperbox might be the way to go to start with. Another route I was thinking was essentially a gyrojet type design. Small rocket propelled projectiles, self-spinning, and the only purpose the plastic gun serves is to provide an initial firing guide (the plastic barrel), a feeding mechanism, and the initial mechanical energy to ignite the cartridge (the hammer).


Hey Mods, since this discussion has ventured away from the politics and into the design, do you think we can get it moved to the Round Table for continued discussion during the Christmas break?

[Monkeyleg]

Looks to be more gun technology-related than political, so it makes sense to me to move it. If another moderator thinks not, just move it back to Politics.

[AJ Dual]

For the record, I think you could make an upper if you reinforced/thickened it sufficiently. In the AR design the aluminum upper and lower halves actually play no part in containing the cartridge during firing. The locking lugs are part of the barrel extension which is more or less permanently screwed onto the barrel. The bolt itself locks into this barrel extension. The only stresses the upper and lower halves deal with are transferring recoil energy, and keeping all the mechanical parts in their correct places during cycling.

Still, and while this isn't a true total plastic design, I think taking bits of small diameter steel rod that you can get at the hardware store, and carefully integrating them into the plastic part as it's being built up by the printer might be a good stop-gap until we get good plastics that can handle the job on their own. Heck, most of the "polymer" parts you have in the gunsmithing industry currently are fiberglass reinforced.


As for making a Liberator Mk-II, a ball and cap pepperbox might be the way to go to start with. Another route I was thinking was essentially a gyrojet type design. Small rocket propelled projectiles, self-spinning, and the only purpose the plastic gun serves is to provide an initial firing guide (the plastic barrel), a feeding mechanism, and the initial mechanical energy to ignite the cartridge (the hammer).


Hey Mods, since this discussion has ventured away from the politics and into the design, do you think we can get it moved to the Round Table for continued discussion during the Christmas break?

I like the gyrojet idea the no stress to the actual firearm is tempting. Except for the fact the rounds sucked then, and I don't think there's any way to improve it since they came out in the first place. Not lethal at close range because they haven't acclerated to full speed, and inaccurate at any medium to long range.

[Balog]

I love the idea of faking up "guns" for a buyback. Still glad I don't live in a place that does them.

[kgbsquirrel]

I like the gyrojet idea the no stress to the actual firearm is tempting. Except for the fact the rounds sucked then, and I don't think there's any way to improve it since they came out in the first place. Not lethal at close range because they haven't acclerated to full speed, and inaccurate at any medium to long range.

True. Still might be useful for zero-G applications though where you don't want recoil. 

It might be interesting if some sort of auto-correcting steering fins could be integrated. I'm reminded of the early attempts at rocketry back in the 20's and 30's. They were having trouble making the rockets go straight up with fixed fins, so a fella created a system where if the rocket tipped in one direction or the other a fin was mechanically actuated to correct it's flight path. Since we've already miniturized laser homing systems to the .50BMG bullet dimensions, the only real prohibition will be bringing down the cost of such a system sufficiently. Bonus points if it's something that can also be printed out.

[RevDisk]

For the record, I think you could make an upper if you reinforced/thickened it sufficiently. In the AR design the aluminum upper and lower halves actually play no part in containing the cartridge during firing. The locking lugs are part of the barrel extension which is more or less permanently screwed onto the barrel. The bolt itself locks into this barrel extension. The only stresses the upper and lower halves deal with are transferring recoil energy, and keeping all the mechanical parts in their correct places during cycling.

Still, and while this isn't a true total plastic design, I think taking bits of small diameter steel rod that you can get at the hardware store, and carefully integrating them into the plastic part as it's being built up by the printer might be a good stop-gap until we get good plastics that can handle the job on their own. Heck, most of the "polymer" parts you have in the gunsmithing industry currently are fiberglass reinforced.


As for making a Liberator Mk-II, a ball and cap pepperbox might be the way to go to start with. Another route I was thinking was essentially a gyrojet type design. Small rocket propelled projectiles, self-spinning, and the only purpose the plastic gun serves is to provide an initial firing guide (the plastic barrel), a feeding mechanism, and the initial mechanical energy to ignite the cartridge (the hammer).

True. Still might be useful for zero-G applications though where you don't want recoil. 

It might be interesting if some sort of auto-correcting steering fins could be integrated. I'm reminded of the early attempts at rocketry back in the 20's and 30's. They were having trouble making the rockets go straight up with fixed fins, so a fella created a system where if the rocket tipped in one direction or the other a fin was mechanically actuated to correct it's flight path. Since we've already miniaturized laser homing systems to the .50BMG bullet dimensions, the only real prohibition will be bringing down the cost of such a system sufficiently. Bonus points if it's something that can also be printed out.

Nearly all 3D printers use ABS plastic. Which has a general useable temperature range of -4 and 176 °F. Not the best range for firearms. Heat dissipation would be interesting, again, unless it was a one-shot. I'd be tempted to put in the work for a single shot disposable pistol or rifle. Especially if the rifle was 1 MOA. Pistol, accuracy not so important.

Guaranteed two things. Such a beautiful weapon would have the laws changed to have it fall under NFA in about two seconds, and government orders would be impressive. Gyrojets would be fun. Especially if not NFA applicable. Good luck on cost. Entirely possible, just again as you point out, cost. 26.5mm gyrojet might be of some interest to folks here.

I'd say polyoxymethylene would be better than ABS, and machined rather than printed. Be sure to use Food Grade Delrin, that is not x-ray transparent. Making x-ray transparent firearms is illegal.

http://www2.dupont.com/Plastics/en_US/assets/downloads/product/delrinfg/DELRIN_FG400XRD_NC010.pdf

[kgbsquirrel]

I've been pondering ways to improve the functional strength of printed objects.

A few ideas:

Replace the ABS with HMPE but that does little to improve the thermal tolerance. You're probably going to have this problem no matter what if a thermoplastic of any sort is used.

Another strength improving design change is to incorporate constant unbroken feeding of aramid or fiberglass thread into the center of the extrusion mass. I think this would work very well with an HMPE printer.

Third idea is to device a printer which consumes the precursors for the creation of aramid fiber (Twaron/Kevlar/Dyneema) but I am unsure what sort of strength you could expect from aramid that is not spun into a thread like usual.

Last idea is to use an acrylate resin in combination with the continuous thread feed. Problem is low sheering strength. Temperature tolerance of Cyanoacrylate is listed only as "+200°F" so not much improvement there.



Personally, what I'd really like to see on the market is a desk-top 5 axis CNC machine, bout a 2 and a half foot cube in size, and less than $5,000.

[KD5NRH]

Once the technology is commonplace and CHEAP, just imagine the potential when the grabbers sponsor "no questions asked" gun buybacks in places like NYC, Chicago, LA, etc. 

You mean like a used lathe and some scrap metal?

Frankly, the potential for 3D printing seems to be more in the single-use small-caliber pen guns.  Print them by the dozen, and if you really wanted a reusable one, you could always have an epoxied-in barrel.

[kgbsquirrel]

You mean like a used lathe and some scrap metal?

Frankly, the potential for 3D printing seems to be more in the single-use small-caliber pen guns.  Print them by the dozen, and if you really wanted a reusable one, you could always have an epoxied-in barrel.

Gonna have to scribble up a simple sketch of that. I'm thinking a small .22LR barrel sleeve. A small bit of sheet steel for a chamber face on the slide, a few more pieces of sheet steel for the firing pin, hammer and sears, and then a bit of piano wire to make springs. Everything else plastic.